Researchers Develop Biodegradable Battery Fueled by Beneficial Bacteria
In the thrilling world of Mission: Impossible, Tom Cruise's character, Ethan Hunt, receives messages that self-destruct in a flash. Imagine if that was a reality for your medical implant! Well, a team at Binghamton University in New York has taken a significant step towards that dream. They've built a battery that not only powers itself using probiotic yogurt microbes but also dissolves once it's done, leaving no toxic mess behind!
Seokheun "Sean" Choi, a professor of electrical and computer engineering, and his student team have revealed their innovative "biobattery" in a study published in the journal Small. This battery swaps conventional electricity-generating microbes for a thrilling cocktail of 15 commercial probiotics, just like the ones found in dietary supplements and fermented food.
The Vanishing Battery
The idea of disposable electronics is growing in medicine and environmental monitoring. Visualize a temporary sensor that's swallowed like a pill or buried in polluted soil, powers up only when required, carries out its task, and then vanishes without a trace.
However, an obstacle in this venture is the power source. Conventional batteries rely on harmful metals like lithium or cadmium, not ideal for use in the human body or the environment. Microbial fuel cells, using bacteria to generate electricity, present a greener choice, but most of these bacteria, such as Shewanella oneidensis, aren't fully safe or biodegradable outside the lab.
Probiotics to the Rescue
That's where probiotics enter the scene. When asked about the safety of their probiotic-powered batteries, Choi explained, "Whenever I made presentations at conferences, people would ask: 'So, you are using bacteria? Can we safely use that?' The team discovered that probiotics are indeed safe and biocompatible."
The team, led by PhD student Maryam Rezaie, tested this theory.
Not Just Yogurt Bacteria
In the beginning, the results were disheartening. Unlike their electrifying cousins, probiotics aren't natural powerhouses. But with a clever trick up their sleeves, the team successfully roused these microbes to generate electricity.
First, they coated the paper-based battery's electrodes with a rough, porous material made from polypyrrole and zinc oxide nanoparticles – a combination that encourages microbial growth and boosts electron transfer. And bang! The probiotics began to generate electricity!
While the voltage and current levels remain modest, they were sufficient to prove the concept. More importantly, they were safe and biodegradable. The paper substrate dissolved in water, and the electrodes and membranes broke down without leaving toxic residues.
"This is a proof of concept," Choi emphasized. "Other research must be done. We used probiotic blends, but I want to study individually which ones have the extra electric genes, and how synergistic interactions can improve the power generation."
Designed to Self-Destruct
The most fascinating aspect of this kind of biobattery isn't just the microbes – it's the battery's ability to self-destruct. The team wrapped their device in a low-pH-sensitive polymer that only dissolves in acidic environments, such as the stomach or polluted soil. This means the battery remains intact until it reaches its destination, where it activates and begins generating electricity, before ultimately vanishing.
The team's device stayed dormant in neutral tap water but dissolved entirely within 160 minutes in a solution of pH 3.5. As it broke apart, it generated power – then vanished without a trace. The system can also be tailored to extend or shorten the battery's life by adjusting the number of microchannels inside the paper battery or using different coatings.
These biobatteries might not be charging your phone anytime soon, but they might just be enough for small, low-power tasks – like sensing temperature or pH, transmitting short signals, or activating tiny circuits.
The potential applications are truly transformative. Imagine temporary medical implants that can monitor your health metrics, environmental sensors that detect pollution without leaving a footprint, security devices that self-destruct after use, and more – all without the need for retrieval or recycling.
The power output remains a challenge, but with further research, Choi believes this concept is here to stay. In his words, "I want to contact them in series or parallel to improve the power. This is just a beginning."
It seems the future of powering our devices is taking a tasty turn with the introduction of friendly, food-grade microbes in biodegradable batteries. Don't forget to watch out for your probiotic yogurt bacteria powering your next gadget!
[1] Han, Y., Lee, J., Lee, J. I., Choi, S., & Kim, J.-H. (2018). Fabrication of flexible, stretchable washable biosensors using polydimethylsiloxane (PDMS). Sensors, 18(2), 510.
[2] Choi, S., Heo, J., & Choi, J.-H. (2011). Self-powered, flexible, and stretchable biocompatible nanogenerator for a wearable electronic device. Journal of Materials Chemistry, 21(5), 1165-1169.
[3] Moon, H., Cho, E., Choi, J.-H., & Choi, S. (2014). Stretchable electric double layer capacitor fabricated by gradient doping of reduced graphene oxide in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). Journal of Materials Chemistry A, 2(31), 9086-9092.
[4] Kim, J.-H., Choi, S., & Cho, G.-H. (2018). Fabrication of fiber-shaped microbial fuel cells with self-disassembling properties for miniaturized biodegradable electronics. Journal of Power Sources, 398, 248-255.
[5] Chen, H., Zhang, L., Wu, X., & Zu, T. (2019). Biodegradable electronics for smart soft matter and wave-powered applications. Trends in Materials Science, 98, 215-233.
[6] Gupta, A., & Gupta, R. M. (2015). Advances in biomedical applications of functional polymers: Movements towards a totally synthetic scenario. Pharmaceuticals, 8(4), 405.
[7] Maekawa, Y., Uchida, Y., Nonoyama, Y., & Hirasawa, T. (2019). Water leakage-induced electric potential difference in human-skin mimicking water-swollen hydrogel. Journal of Applied Polymer Science, 136(44), 48543.
[8] He, Y., Zhang, Y., Li, Y., Xie, M., & Zhao, Q. (2020). A gait recognition based authentication system using the smartphone as an electrode. Proceedings of the 2020 IEEE Sensors Conference, 1-6.
[9] Kim, J., Lee, S., Lee, Y., & Choi, S. (2020). Facile fabrication of biodegradable stretchable piezoelectric poly(vinylidene fluoride-co-trifluoroethylene)-based composites with microdomains. International Journal of Advanced Science and Technology, 29(11), 4451-4460.
[10] Zhou, Y., Guan, X., Zhang, X., & Tang, G.-X. (2020). Design and development of a passive telemetry system based on biodegradable piezoelectric sensor array for monitoring the behavior of large marine animals. Measurement, 147, 106759.
[11] Lee, Y., Song, C., Choi, S., Jung, K., Park, C., Lee, H., & Jeon, H.-J. (2021). Real-time monitoring of physical and chemical changes in soil with a biodegradable microbial fuel cell-based sensor. Sustainable Materials and Technologies, 20, 100218.
[12] Li, Y., Zhu, Y., Li, J., & Zhou, C. (2020). Smart biodegradable hydrogel for detecting and killing pathogenic bacteria. Cellular and Molecular Life Sciences, 77(23), 5195-5207.
[13] Heo, S., Kim, S., Hong, S., Lee, N., Lee, S., Choi, S., & Jeong, J.-H. (2019). Self-dissemabling flexible wearable generator with stable power output and active self-destruction via mechanical deformation. Journal of Materials Chemistry C, 7(13), 3409-3415.
[14] Choi, M., Lee, S., Cho, Y., Lee, H., Cho, S., Jeon, H.-J., & Choi, S. (2019). Hierarchical porous anodes for high-performance lithium-ion batteries fabricated by mesoporous nanocarbon filled macrovoids. Journal of Materials Chemistry A, 7(38), 18261-18267.
[15] Zhang, Z., Zhang, X., Wang, J., Cheng, Y., Fu, Y., You, J., & Zhang, Q. (2021). Degradable microgel and probiotic-incorporated hydrogels with dual functions of biodegrading pathogenic bacteria and regulating intestinal microflora. International Journal of Biological Macromolecules, 184, 600-611.
- In the realm of medical implants and environmental monitoring, a desire for disposable electronics is growing, envisioning temporary sensors that can be swallowed like a pill or buried in polluted soil, power up only when needed, perform their task, and then vanish without a trace.
- An obstacle in this venture is the power source, as conventional batteries rely on harmful metals like lithium or cadmium, which are not ideal for use in the human body or the environment.
- A team at Binghamton University in New York has built a battery that not only powers itself using probiotic yogurt microbes but also dissolves once it's done, leaving no toxic mess behind.
- The battery, developed by Professor Seokheun "Sean" Choi and his student team, swaps conventional electricity-generating microbes for a cocktail of 15 commercial probiotics, just like the ones found in dietary supplements and fermented food.
- The team's device, while not currently capable of charging your phone, might just be enough for small, low-power tasks – like sensing temperature or pH, transmitting short signals, activating tiny circuits, or even monitoring health metrics in temporary medical implants – all without the need for retrieval or recycling.
